A depth sensing pixel is used to determine a distance between an image sensor and an object. An image sensing pixel is used to capture an image of the object. A composite pixel includes a depth sensing pixel combined with an image sensing pixel to determine a distance to the object and capture an image of the object.
In a structure including both the image sensing pixel and the depth sensing pixel, the outputs of the depth sensing pixel and the image sensing pixels are output using a time multiplexing strategy, in some approaches. The time multiplexing strategy allocates one frame to the depth sensing pixel and one frame to the image sensing pixel in an alternating manner.
In approaches where the depth sensing pixel is positioned behind the image sensing pixel so that incident light passes through the image sensing pixel to reach the depth sensing pixel, formation of the depth sensing pixel depends on the precision of the fabrication tools. In some approaches, the depth sensing pixel is located in a non-overlapping position with the image sensing pixel. In some approaches, the depth sensing pixel is located around a periphery of the image sensing pixel.